Load device for evaluating performance of steering device

Abstract

An inventive load apparatus for performance evaluation of a steering system has a simple construction and yet is capable of faithfully reproducing a tire load observed when the steering system is actually mounted on a motor vehicle. A compression load spring device ( 12 ) includes a piston ( 18 ) which is axially movable within a cylinder ( 17 ), and a pair of springs ( 20, 21 ) which resiliently urge the piston ( 18 ) to hold the piston ( 18 ) in a force balanced state at a neutral position in the cylinder. The piston ( 18 ) is connected to a rod ( 19 ) having one end ( 19 a) serving as a load output portion. A load outputted from the load output portion ( 19 a) is multiplied by a preset factor by means of a lever mechanism ( 13 ), and the resulting load is applied to the steering system ( 30 ).

1 . A load apparatus for steering system performance evaluation, comprising:
 a load generating mechanism including a piston which is axially movable within a cylinder, a rod which is connected to the piston and has one end projecting from the cylinder and serving as a load output portion, the rod being axially movable as the piston is moved, and a pair of resilient members which respectively apply resilient forces to the piston from axially opposite sides of the piston to hold the piston in a force balanced state at a predetermined neutral position in the cylinder; and   a load transmission mechanism having opposite ends, one of which is connected to the load output portion of the load generating mechanism and the other of which is connectable to a steering output portion of a steering system to be subjected to the performance evaluation, the load transmission mechanism being configured to multiply a load outputted from the load output portion by a preset factor and transmit the resulting load to the steering output portion.   
   
   
       2 . A load apparatus for steering system performance evaluation as set forth in  claim 1 , wherein the cylinder is filled with a viscous material. 
   
   
       3 . A load apparatus for steering system performance evaluation as set forth in  claim 2 , wherein the load transmission mechanism includes a lever mechanism having a fulcrum, an action point and a power point, the action point being connected to the load output portion, the power point being connected to the steering output portion. 
   
   
       4 . A load apparatus for steering system performance evaluation as set forth in  claim 3 , wherein a ratio of a distance between the fulcrum and the action point to a distance between the fulcrum and the power point is variable. 
   
   
       5 . A load apparatus for steering system performance evaluation as set forth in  claim 4 , further comprising a frictional force applying mechanism which is connectable to the steering output portion of the steering system to apply a preset frictional force to the steering output portion. 
   
   
       6 . A load apparatus for steering system performance evaluation as set forth in  claim 1 , wherein the load transmission mechanism includes a lever mechanism having a fulcrum, an action point and a power point, the action point being connected to the load output portion, the power point being connected to the steering output portion. 
   
   
       7 . A load apparatus for steering system performance evaluation as set forth in  claim 6 , further comprising a frictional force applying mechanism which is connectable to the steering output portion of the steering system to apply a preset frictional force to the steering output portion. 
   
   
       8 . A load apparatus for steering system performance evaluation as set forth in  claim 4 , further comprising a frictional force applying mechanism which is connectable to the steering output portion of the steering system to apply a preset frictional force to the steering output portion. 
   
   
       9 . A load apparatus for steering system performance evaluation as set forth in  claim 3 , further comprising a frictional force applying mechanism which is connectable to the steering output portion of the steering system to apply a preset frictional force to the steering output portion. 
   
   
       10 . A load apparatus for steering system performance evaluation as set forth in  claim 2 , further comprising a frictional force applying mechanism which is connectable to the steering output portion of the steering system to apply a preset frictional force to the steering output portion. 
   
   
       11 . A load apparatus for steering system performance evaluation as set forth in  claim 1 , further comprising a frictional force applying mechanism which is connectable to the steering output portion of the steering system to apply a preset frictional force to the steering output portion.